Well-known member

SWAP can be used by the server when idling. What happens is that it puts some of the Memory into SWAP, 'just in case', but it doesn't remove the data from regular memory. The level to which it does that is determined by swappiness. If you want to stop it, set swappiness to zero. But as it only writes during idle and doesn't remove anything from RAM, it should not be impacting on your system at all.